An FeNi alloy composition comprising an L1.sub.0-type FeNi ordered phase is provided, which satisfies at least one of the conditions that the sum of the content of Fe and the content of Ni is 90 at. % or less and that the FeNi alloy composition contains Si, and preferably satisfies at least one of the conditions that the ratio of the content of Fe to the content of Ni is 0.3 or more and 5 or less and that the sum of the content of Fe and the content of Ni is 65 at. % or more.

A magnetic device includes a substrate and an array including a plurality of magnetic particles, in which a magnetic dipole moment direction of each magnetic particle in a majority of the magnetic particles in the array alternates with respect to a magnetic dipole direction of a directly adjacent magnetic particle or directly adjacent magnetic particles in the array.

A method for producing a nanoheterostructured permanent magnet includes a first step of preparing a raw material solution by dissolving, in a solvent, (1) a block copolymer comprising polymer block components that are immiscible but linked to each other, (2) a first inorganic precursor which is one of a hard magnetic material precursor and a soft magnetic material precursor, and (3) a second inorganic precursor which is the other of the hard magnetic material precursor and the soft magnetic material precursor, and a second step including a phase-separation treatment for forming a nanophase-separated, a conversion treatment for converting the hard magnetic material precursor and the soft magnetic material precursor to a hard magnetic material and a soft magnetic material, respectively, and a removal treatment for removing the block copolymer from the nanophase-separated structure.

A nanoheterostructured permanent magnet includes a hard magnetic material and a soft magnetic material of which one inorganic component is a matrix, and of which the other inorganic component is three-dimensionally and periodically arranged in the matrix, in a shape selected from the group consisting of a spherical shape, a columnar shape, and a gyroid shape, the nanoheterostructured permanent magnet having a three-dimensional periodic structure whose average value of one unit length of a repeated structure is 1 nm to 100 nm.

A magnetic device includes a substrate and an array including a plurality of magnetic particles, in which a magnetic dipole moment direction of each magnetic particle in a majority of the magnetic particles in the array alternates with respect to a magnetic dipole direction of a directly adjacent magnetic particle or directly adjacent magnetic particles in the array.

The present invention relates to a magnetic material containing a magnetic alloy particle having an ordered crystal structure. The magnetic material according to the present invention is the one composed of a magnetic alloy particle having crystal magnetic anisotropy and being composed of an FePt alloy, a CoPt alloy, an FePd alloy, a Co.sub.3Pt alloy, an Fe.sub.3Pt alloy, a CoPt.sub.3 alloy, an FePt.sub.3 alloy, or the like, and a silica carrier covering the magnetic alloy, in which the silica carrier contains an alkali-earth metal compound such as an oxide, hydroxide or silicate compound of Ba, Ca, or Sr. The magnetic material according to the present invention is excellent in magnetic properties such as coercive force.

A one-pot microwave synthesis of Fe.sub.0.65Pt.sub.0.35@Co allows systematic growth of the soft-magnet Co shell (0.6 nm to 2.7 nm thick) around the hard-magnet Fe.sub.0.65Pt.sub.0.35 core (5 nm in diameter). Controlled growth leads to a four-fold enhancement in energy product of the core-shell assembly as compared to the energy product of bare Fe.sub.0.65Pt.sub.0.35 cores. The simultaneous enhancement of coercivity and saturation moment reflects the onset of theoretically predicted exchange spring behavior. The demonstration of nanoscale exchange-spring magnets will result in improved high-performance magnet design for energy applications.

A magnetic device includes a substrate and an array including a plurality of magnetic particles, in which a magnetic dipole moment direction of each magnetic particle in a majority of the magnetic particles in the array alternates with respect to a magnetic dipole direction of a directly adjacent magnetic particle or directly adjacent magnetic particles in the array.

A FeNi ordered alloy structural body includes a support having a surface, and particles disposed on the surface of the support with gaps therebetween. Each of the particles contains an L1.sub.0-type FeNi ordered alloy phase. In a method for manufacturing the FeNi ordered alloy structural body, the support is prepared, and particles of an FeNi disordered alloy are dispersed on the surface of the support with gaps therebetween. A nitriding treatment is performed to the particles of the FeNi disordered alloy to form particles in which nitrogen is incorporated. After the nitriding treatment, a denitrification treatment is performed to desorb the nitrogen from the particles, thereby to form the particles containing the L1.sub.0-type FeNi ordered alloy phase.